GZip files contain one or more Sections. Each Section, on disk, begins
with a GZip Header, then stores the compressed data itself, and finally
stores a GZip Footer.

The Header identifies the file as a GZip file, records the original
modification date and time, and, in some cases, also records the original
filename and comments.

The Footer contains a GZip CRC32 checksum over the decompressed data as
well as a 32-bit length of the decompressed data. The module
Data.Hash.CRC32.GZip is used to validate stored CRC32 values.

The vast majority of GZip files contain only one Section. Standard tools
that work with GZip files create single-section files by default.

Multi-section files can be created by simply concatenating two existing
GZip files together. The standard gunzip and zcat tools will simply
concatenate the decompressed data when reading these files back. The
decompress function in this module will do the same.

When reading data from this module, please use caution regarding how you access
it. For instance, if you are wanting to write the decompressed stream
to disk and validate its CRC32 value, you could use the decompress
function. However, you should process the entire stream before you check
the value of the Bool it returns. Otherwise, you will force Haskell to buffer
the entire file in memory just so it can check the CRC32.